Brouéʼs abelian defect group conjecture for the sporadic simple Janko group J4 revisited

We show that the 3-block of the sporadic simple Janko group J4 with defect group C3×C3, and the principal 3-block of the alternating group A8 are Puig equivalent, answering a question posed in our previous paper. To accomplish this, we apply computational techniques, in particular an explicit version of the Brauer construction.